1. Field of the Invention
This invention relates to stabilizing elements and tensioning linkages of a sort used in agricultural implements, although the invention is not limited to such usage.
2. Brief Description of the Prior Art
In the use of agricultural tractors, two types of stabilizing linkages have frequently been used in the three-point hitch connection for the purpose of stabilizing an implement connected to, and towed behind, the tractor. One of these types of stabilizing elements is an elongated rigid bar having holes in its opposite ends. Two of such stabilizing bars are connected at opposite sides of the central hitch link in the tractor and function to prevent swaying of the agricultural implement from side to side, or canting of the implement as it is towed behind the tractor.
The rigid bar type stabilizing elements, as used for stabilizing the movements of an implement towed behind an agricultural tractor, present some difficulty in usage, since it is always necessary to shift the equipment between which the stabilizing bars are connected by a sufficient amount that the holes provided at opposite ends of the bars for effecting connection are lined up with the appropriate interlocking studs provided on the implement and on the tractor. At times procuring such alignment is a strenuous and frustrating task.
In another type of stabilizing device which has been used in the hook-up between towed implements and agricultural tractors, elongated flexible tensioning linkages or stabilizing members have been used at the same locations where the rigid stabilizer bars described above have been used. In these flexible tensioning linkages, a turnbuckle sleeve is generally interposed between flexible members, such as a pair of chains, with the chains being drawn tight after their ends are connected at the implement and tractor so as to tension the linkage between the points of connection. This is effected by rotating the turnbuckle sleeve until the desired degree of tensioning is attained. Usually this is accomplished manually. The tensioning of the flexible tensioning linkages, which are horizontally spaced from each other and connected to opposite sides of the towed implement, when functioning conjunctively with the three-point linkage provided for hooking up the implement, acts to stabilize the implement, and to prevent it from swaying from side to side.
The flexible tensioning linkages used for stabilization in the manner described provide an advantage over rigid stabilizer bars, in that there is no difficulty in connecting the opposite ends of the linkages to the provided points of connection on the implement and on the tractor. In general, such flexible linkages can be much more quickly and easily installed than can the rigid stabilizer bars. On the other hand, difficulty has been experienced in maintaining the tension in the flexible tensioning linkages after this has been set by manual adjustment. Loss of tension in the tensioning linkages occurs as a result of the turnbuckle sleeves undergoing an unthreading rotation as vibrational forces are transmitted to the sleeve through the chain sections which it interconnects. In order to prevent such reverse rotation of the turnbuckle sleeve having the effect of relieving the tension in the tensioning linkages, a pair of locking nuts have generally been provided on the threaded members carried by the chain sections and threaded into the turnbuckle linkage. These locking nuts are manually threaded up against the opposite ends of the turnbuckle sleeve so that the sleeve, by frictional contact with the nuts, is prevented from undergoing undesirable rotation under the influence of vibrational stresses. It has frequently been difficult and occasionally impossible, however, to sufficiently manually tighten the locking nuts against the turnbuckle sleeve to prevent the nuts from working loose enough to permit the sleeve to undergo unthreading rotation over extended periods of usage of the tractor and implement.